Staples recently charged $3.79 per ream (package of 500 sheets) of regular paper and $5.49 per ream of paper made of recycled fibers. last semester, valley collage spent $582.44 for 116 reams of paper. how many of each type were purchased?

Respuesta :

Given

regular paper costs $3.79 per ream

recycled paper costs $5.49 per ream

$582.44 was spent for 116 reams

Find

the numbers of reams of each type that were purchased

Solution

Let r and g represent the numbers of reams of regular and recycled ("green") paper, respectively.

... r + g = 116 . . . . . . . . 116 reams were purchased

... 3.79r + 5.49g = 582.44 . . . . this is the total cost of the purchase

Solve the first equation for r and substitute that into the second equation.

... r = 116 - g

... 3.79(116 - g) + 5.49g = 582.44 . . . . . use the expression for r

... 1.70g + 439.64 = 582.44 . . . . . . . . . simplify

... g = (582.44 -439.64)/1.70 = 84 . . . . subtract the constant, divide by 1.70

... r = 116 -84 = 32 . . . . . . . . . . . . . . . . . use the equation for r

32 regular reams and 84 recycled reams were purchased